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<FONT color="green">001</FONT>    <a name="line.1"></a>
<FONT color="green">002</FONT>    /*<a name="line.2"></a>
<FONT color="green">003</FONT>     * Copyright (C) 2011 Archie L. Cobbs. All rights reserved.<a name="line.3"></a>
<FONT color="green">004</FONT>     *<a name="line.4"></a>
<FONT color="green">005</FONT>     * $Id: TimedWait.html 4 2011-02-05 22:22:47Z archie.cobbs $<a name="line.5"></a>
<FONT color="green">006</FONT>     */<a name="line.6"></a>
<FONT color="green">007</FONT>    <a name="line.7"></a>
<FONT color="green">008</FONT>    package org.dellroad.stuff.java;<a name="line.8"></a>
<FONT color="green">009</FONT>    <a name="line.9"></a>
<FONT color="green">010</FONT>    <a name="line.10"></a>
<FONT color="green">011</FONT>    /**<a name="line.11"></a>
<FONT color="green">012</FONT>     * Utility class for performing timed waits on objects.<a name="line.12"></a>
<FONT color="green">013</FONT>     *<a name="line.13"></a>
<FONT color="green">014</FONT>     * @see Object#wait<a name="line.14"></a>
<FONT color="green">015</FONT>     */<a name="line.15"></a>
<FONT color="green">016</FONT>    public final class TimedWait {<a name="line.16"></a>
<FONT color="green">017</FONT>    <a name="line.17"></a>
<FONT color="green">018</FONT>        private TimedWait() {<a name="line.18"></a>
<FONT color="green">019</FONT>        }<a name="line.19"></a>
<FONT color="green">020</FONT>    <a name="line.20"></a>
<FONT color="green">021</FONT>        /**<a name="line.21"></a>
<FONT color="green">022</FONT>         * Wait (using {@link Object#wait(long) Object.wait()}) up to a given time limit for some predicate to become true.<a name="line.22"></a>
<FONT color="green">023</FONT>         * This method correctly handles {@link Object#wait spurious wakeups}, restarting the wait loop as necessary.<a name="line.23"></a>
<FONT color="green">024</FONT>         *<a name="line.24"></a>
<FONT color="green">025</FONT>         * &lt;p&gt;<a name="line.25"></a>
<FONT color="green">026</FONT>         * This method assumes that {@code obj} will be notified whent the predicate becomes true and that the current thread<a name="line.26"></a>
<FONT color="green">027</FONT>         * is already synchronized on {@code obj}.<a name="line.27"></a>
<FONT color="green">028</FONT>         *<a name="line.28"></a>
<FONT color="green">029</FONT>         * @param obj       object to sleep on; must already be locked<a name="line.29"></a>
<FONT color="green">030</FONT>         * @param timeout   wait timeout in milliseconds, or zero for an infinite wait<a name="line.30"></a>
<FONT color="green">031</FONT>         * @param predicate predicate to test<a name="line.31"></a>
<FONT color="green">032</FONT>         * @return true if the predicate became true before the timeout, otherwise false<a name="line.32"></a>
<FONT color="green">033</FONT>         * @throws IllegalArgumentException     if {@code timeout} is negative<a name="line.33"></a>
<FONT color="green">034</FONT>         * @throws IllegalMonitorStateException if {@code obj} is not already locked<a name="line.34"></a>
<FONT color="green">035</FONT>         * @throws InterruptedException         if the current thread is interrupted<a name="line.35"></a>
<FONT color="green">036</FONT>         */<a name="line.36"></a>
<FONT color="green">037</FONT>        public static boolean wait(Object obj, long timeout, final Predicate predicate) throws InterruptedException {<a name="line.37"></a>
<FONT color="green">038</FONT>            if (timeout &lt; 0)<a name="line.38"></a>
<FONT color="green">039</FONT>                throw new IllegalArgumentException("timeout = " + timeout);<a name="line.39"></a>
<FONT color="green">040</FONT>            long startTime = timeout &gt; 0 ? System.currentTimeMillis() : 0;<a name="line.40"></a>
<FONT color="green">041</FONT>            while (!predicate.test()) {<a name="line.41"></a>
<FONT color="green">042</FONT>                if (timeout &lt; 0)<a name="line.42"></a>
<FONT color="green">043</FONT>                    return false;<a name="line.43"></a>
<FONT color="green">044</FONT>                obj.wait(timeout);<a name="line.44"></a>
<FONT color="green">045</FONT>                if (timeout &gt; 0) {<a name="line.45"></a>
<FONT color="green">046</FONT>                    long stopTime = System.currentTimeMillis();<a name="line.46"></a>
<FONT color="green">047</FONT>                    timeout -= stopTime - startTime;<a name="line.47"></a>
<FONT color="green">048</FONT>                    if (timeout == 0)               // don't convert the last millisecond into an infinite wait<a name="line.48"></a>
<FONT color="green">049</FONT>                        timeout = -1;<a name="line.49"></a>
<FONT color="green">050</FONT>                    startTime = stopTime;<a name="line.50"></a>
<FONT color="green">051</FONT>                }<a name="line.51"></a>
<FONT color="green">052</FONT>            }<a name="line.52"></a>
<FONT color="green">053</FONT>            return true;<a name="line.53"></a>
<FONT color="green">054</FONT>        }<a name="line.54"></a>
<FONT color="green">055</FONT>    }<a name="line.55"></a>
<FONT color="green">056</FONT>    <a name="line.56"></a>




























































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